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+{
+"cells": [
+ {
+		   "cell_type": "markdown",
+	   "metadata": {},
+	   "source": [
+       "# Chapter 1: Interference of Light"
+	   ]
+	},
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 1.10: Fringe_width.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 1.10 // fringe width\n",
+"clc;\n",
+"clear;\n",
+"//given data :\n",
+"b1=0.087;// initally fringe width in mm\n",
+"//when distance given in ratio \n",
+"r=.75;// ratio\n",
+"b=b1/r\n",
+"disp(b,'width of fringes in mm')"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 1.11: distance_between_coherent_sources.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 1.11 // separation between coherent source  \n",
+"clc;\n",
+"clear;\n",
+"//given data :\n",
+"u=1.5;//referactive index of bi-prism\n",
+"al=2*%pi/180;//angle in radian\n",
+"a=.1;// distance between source & prism in m\n",
+"d=2*a*(u-1)*al;// distance between slits in m\n",
+"disp(d,'separation between coherent source in meter')"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 1.12: Refractive_Index_of_sheet.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 1.12 // refractive index of sheet\n",
+"clc;\n",
+"clear;\n",
+"//given data :\n",
+"w=5460D-10;// wavelength in m\n",
+"n=6;// number of fringe shifted\n",
+"t=6.3D-6;//thickness of material\n",
+"u=(n*w)/t +1; // equation for fefractive index\n",
+"disp(u,'refractive index of sheet')"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 1.14: Thickness_of_plate.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 1.4 // thickness of plate \n",
+"clc;\n",
+"clear;\n",
+"//given data :\n",
+"u=1.5;//referactive index of glass plate\n",
+"r=60;// refraction angle in degree\n",
+"r=r*%pi/180;// to convert in radian\n",
+"w=5890D-10;// wavelength in m\n",
+"//for least thickness\n",
+"t=w/(2*u*cos(r));\n",
+"t=t*1D10;// to convert in angstrom\n",
+"disp(t,'thickness of plate in A')"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 1.15: Film_Thickness.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 1.15 // flim thickness\n",
+"clc;\n",
+"clear;\n",
+"//given data :\n",
+"u=1.5;//referactive index of oil\n",
+"i=30;// incident angle in degree\n",
+"i=i*%pi/180;//to convert in radian\n",
+"n=8;//8th dark band\n",
+"w=5890D-10;// wavelength in m\n",
+"r=sqrt(1-(sin(i)/u)^2);//cos of received angle\n",
+"t=n*w/(2*u*r);//formula of thickness\n",
+"t=t*1D3;//to convert in mm\n",
+"disp(t*1D-3,'flim thickness in m')"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 1.16: Order_of_interference.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 1.16 // order of dark band\n",
+"clc;\n",
+"clear;\n",
+"//given data :\n",
+"u=4/3;//referactive index of soap flim\n",
+"t=1.5D-6;//thickness of soap flim\n",
+"i=60;//incident angle in degree\n",
+"i=i*%pi/180;// incident angle in radian\n",
+"w=5D-7;// wavelength in m\n",
+"r=sin(i)/u;//sin of refracted angle\n",
+"R=asin(r);//refracted angle in radian\n",
+"n=2*u*t*cos(R)/w\n",
+"n=floor(n)\n",
+"disp(n,'order of dark band')"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 1.17: Fringe_Width.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 1.17 // fringe width\n",
+"clc;\n",
+"clear;\n",
+"//given data :\n",
+"x=.15;// air flim base width in m\n",
+"w=6D-7;// wavelength in m\n",
+"ab=0.05D-3;//length wire in m\n",
+"u=1;//refractive index of air\n",
+"theta=ab/x;\n",
+"b=w/(2*u*theta);//fringes width\n",
+"disp(b,'width of fringes in meter')"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 1.18: Wavelength_of_light.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 1.18 // wavvelength of light\n",
+"clc;\n",
+"//given data :\n",
+"b=.5D-2;//distace between succesive fringes in m\n",
+"u=1.4;//refractive index of cellophane\n",
+"a=10;//angle of wedge in sec\n",
+"a=a*%pi/(60*60*180);//to convert in radian\n",
+"w=2*u*a*b;\n",
+"w=w*1D10;//to convert in A\n",
+"disp(w,'wavelength of light used in A')\n",
+"\n",
+"//note: Pi is taken as 22/7 in the textbook."
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 1.19: Wedge_angle.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 1.19 // angle of wedge \n",
+"clc;\n",
+"clear;\n",
+"//given data :\n",
+"x=1D-2;//distace of mth dark band\n",
+"w=6D-7;// wavelength in m\n",
+"m=10;//number of dark band\n",
+"a=m*w/(2*x)\n",
+"disp(a,'angle of wedge in radian')\n",
+"//note: answer in textbook is in seconds"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 1.1: fringe_width.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 1.1 // fringe width\n",
+"clear;\n",
+"clc;\n",
+"//given data :\n",
+"d=5D-4;// distance between slits in m\n",
+"w=5890D-10;// wavelength in m\n",
+"D=0.5;//distance between source and screen in m\n",
+"b=D*w/d;//fringes width\n",
+"disp(b,'width of fringes in meter')"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 1.20: No_of_Dark_bands.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 1.20 // number of dark band\n",
+"clc;\n",
+"clear;\n",
+"//given data :\n",
+"t=0.01;//thickness of oil film\n",
+"t=t*1D-3;//to convert in m\n",
+"u=1.4;//refractive index of oil\n",
+"w1=4D-7;// first wavelength in m\n",
+"w2=5D-7;// second wavelength in m\n",
+"a=%pi/4;//flim placed at angle\n",
+"cosr=sqrt(1-(sin(a)/u)^2);//formula\n",
+"n1=2*u*t*cosr/w1;\n",
+"n2=2*u*t*cosr/w2;\n",
+"n1=floor(n1);//to convert in integer\n",
+"n2=floor(n2);//to convert in integer\n",
+"n=n1-n2;//number of dark band\n",
+"disp(n,'number of dark band')"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 1.21: Radius_of_lens.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 1.21 // radius of lens\n",
+"clc;\n",
+"clear;\n",
+"//given data :\n",
+"w=5890D-10;//wavelength used in m\n",
+"d=.01;//diameter of dark ring in m\n",
+"r=%pi/6;//angle that light passes in radian\n",
+"n=3;// order of ring\n",
+"u=1;// refractive index of medium  between lens  and plate\n",
+"R=u*(d^2)*cos(r)/(4*n*w);// radius of lens in m\n",
+"disp(R,'radius of lens in m')"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 1.22: Wavelength_of_light.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 1.22 // wavelength used\n",
+"clc;\n",
+"clear;\n",
+"//given data :\n",
+"R=3;//radius of lens in m\n",
+"n=8;// order of bright ring\n",
+"D=.72D-2;// diameter of bright ring in m\n",
+"u=1;// refractive index of medium between lens  and plate\n",
+"w=(D^2)/((2*n-1)*2*R);// wavelength used in m\n",
+"w=w*1D10;//to convert in A\n",
+"disp(w,'wavelength of light used in A')"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 1.23: Distance_between_rings.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 1.23 // distance between rings\n",
+"clc;\n",
+"clear;\n",
+"//given data :\n",
+"R1=100;//radii of curvature in cm\n",
+"R2=R1;// given\n",
+"w=5400D-8;// wavelength of light in m\n",
+"n1=5;// order of ring for case one\n",
+"r1=sqrt(n1*w/((1/R1)+(1/R2)));//radii of curvature in cm\n",
+"n2=15;// order of ring for second case\n",
+"r2=sqrt(n2*w/(1/R1+1/R2));// radii of curvature in cm\n",
+"d=r2-r1;// distance between rings\n",
+"disp(d,'distance between rings in cm')\n",
+""
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 1.24: Refractive_Index_of_liquid.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 1.24 // refractive index \n",
+"clc;\n",
+"clear;\n",
+"//given data :\n",
+"d1=.3;// diameter of ring in cm\n",
+"d2=.25;//diameter of ring(in cm) after placing in medium\n",
+"u=(d1/d2)^2;// refractive index of medium\n",
+"disp(u,'refractive index of medium')"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 1.25: Diameter_of_Ring.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 1.25 // diameter of bright ring\n",
+"clc;\n",
+"clear;\n",
+"//given data :\n",
+"w=6D-7;// wavelength used in m\n",
+"R1=3;//radius of curvature of convex lens in m\n",
+"R2=4;//radius of curvature of concave lens in m\n",
+"n=13;// order of ring\n",
+"r=sqrt((2*n-1)*w/(2*(1/R1-1/R2)));// radius of ring\n",
+"disp(2*r,'diameter of bright ring in m')\n",
+"\n",
+""
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 1.26: Thickness_of_film.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 1.26 // thickness of flim\n",
+"clc;\n",
+"clear;\n",
+"//given data :\n",
+"u=1.5;// refractive index  of flim between lens and plate\n",
+"m=10;//no. of fringes shifted in experiment\n",
+"w=5890D-10;// wavelength of light used in m\n",
+"t=m*w/(2*(u-1));// thickness of plastic flim in m\n",
+"t=t*1D9;// to convert in nm\n",
+"disp(t,'thickness of flim in nm(nanometer)')"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 1.27: Refractive_Index.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 1.27 // refractive index\n",
+"clc;\n",
+"clear;\n",
+"//given data :\n",
+"n=150;//no. of frnges shifted\n",
+"w=4D-7;// wavelength of light used\n",
+"l=.2;//length of tube in m\n",
+"u=n*w/(2*l) +1\n",
+"disp(u,'refractive index of medium ')\n",
+"\n",
+""
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 1.28: Thickness_of_film.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 1.28 // thickness of flim\n",
+"clc;\n",
+"clear;\n",
+"//given data :\n",
+"w=589D-9;//wavelength of light used in m\n",
+"u=1.45;// refractive index of medium between lens and plate\n",
+"n=6.5;// fringes shifted\n",
+"t=n*w/(2*(u-1));// thickness of flim in m\n",
+"t=t*1D9;//to convert in nano meter\n",
+"disp(t,'thickness of flim in nm(nanometer)')"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 1.29: Distance_between_position_of_mirrors.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 1.29 // distance between successive poitions of movable mirror\n",
+"clc;\n",
+"clear;\n",
+"//given data :\n",
+"w1=5896D-8;//one wavelength of light used in cm\n",
+"w2=5890D-8;// second wavelength of light used in cm \n",
+"d=w1*w2/(2*(w1-w2));// distance between sucessive position of mirror in cm\n",
+"disp(d,'dustance between sucessive position of mirror in cm')   "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 1.2: slit_separatio.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 1.2 // double slit separation\n",
+"clear;\n",
+"clc;\n",
+"//given data :\n",
+"w=5100D-10;// wavelength in m\n",
+"D=2;//distance between source and screen in m\n",
+"n=10;// number of fringes\n",
+"x=0.02;//width of all n fringes in m\n",
+"b=x/n;//fringes width\n",
+"d=D*w/b;//double slit width\n",
+"disp(d,'double slit separation in meter')\n",
+""
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 1.30: Velocity_of_Light_in_liquid.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 1.30 // velocity of light in medium\n",
+"clc;\n",
+"clear;\n",
+"//given data :\n",
+"d1=.3;// diameter of ring in cm\n",
+"d2=.25;//diameter of ring(in cm) after placing in medium\n",
+"c=3D8;//speed of light in m/s\n",
+"u=(d2/d1)^2;// refractive index of medium\n",
+"v=u*c;// velocity of light in fluid\n",
+"disp(v,'velocity of light in liquid in m/s')"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 1.31: Film_Thickness.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 1.31 // thickness of flim\n",
+"clc;\n",
+"clear;\n",
+"//given data :\n",
+"w1=6.1D-5;//wavelength of light fall in cm\n",
+"w2=6D-5;// wavelength of light fall in cm\n",
+"u=1.33;// refractive index soap flim\n",
+"si=4/5;//sine of incident angle\n",
+"t=w1*w2/(2*(w1-w2)*sqrt(u^2-si^2))\n",
+"disp(t,'thickness of flim in cm')\n",
+""
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 1.32: wavelength_of_light.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 1.32 // wavelength of light \n",
+"clc;\n",
+"//given data :\n",
+"n1=5;//order of ring\n",
+"n2=25;// order of ring\n",
+"m=n2-n1;//difference of ring order\n",
+"R=100;//radius of curvature in cm\n",
+"d1=.3;//diameter of ring n cm\n",
+"d2=.8;//diameter of ring in cm\n",
+"w=(d2^2-d1^2)/(4*R*m);//wavelength in cm \n",
+"disp(w,'wacelength of light in cm')"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 1.33: diameter_of_ring.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 1.33 // diameter of ring\n",
+"clc\n",
+"clear;\n",
+"//given data :\n",
+"n1=4;//order of ring\n",
+"n2=12;// order of ring\n",
+"m=n2-n1;//difference of ring order\n",
+"n=20;// order of ring to find\n",
+"//let k=4*wavelength**R\n",
+"d1=.4;// diameter of first ring in cm\n",
+"d2=.7;//diameter of second ring in cm\n",
+"k=(d2^2-d1^2)/m;\n",
+"d=sqrt(n*k);// diameter of ring in cm\n",
+"disp(d,'diameter of ring in cm')\n",
+"\n",
+"//note: Wrong answer in the textbook.\n",
+"\n",
+"\n",
+"\n",
+"\n",
+"\n",
+""
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 1.3: wave_length.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 1.3 // wavelength of ligth  \n",
+"clc;\n",
+"clear;\n",
+"//given data :\n",
+"d=19D-4;// distance between slits in m\n",
+"D=1;//distance between source and screen in m\n",
+"b=.31D-3;//fringes width in m\n",
+"w=b*d/D;// wavelength in m\n",
+"w=w*1D10;// to convert in A\n",
+"disp(w,'wavelength of light in A(angstrom)')"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 1.4: position_of_fringe.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 1.4 // position of fringe\n",
+"clc;\n",
+"clear;\n",
+"//given data :\n",
+"d=2D-3;// distance between slits in m\n",
+"w=5890D-10;// wavelength in m\n",
+"D=0.04;//distance between source and screen in m\n",
+"n=10;// number of fringe which is to locate\n",
+"x=n*D*w/d;//position of fringe \n",
+"disp(x,'position of nth fringes in meter')"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 1.5: Distance_between_coherent_source.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 1.5 // distance between coherent source\n",
+"clc;\n",
+"//given data :\n",
+"b=9.424D-4;//fringes width in m\n",
+"w=5890D-10;// wavelength in m\n",
+"a=0.05;// distance between source & prism in m\n",
+"c=0.75;// distance between prism & screen in m\n",
+"D=a+c;//distance between source and screen in m\n",
+"d=(D*w)/b;//distance between coherent source\n",
+"disp(d,'distance between coherent source in meter')"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 1.6: Fringe_width.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 1.6 // fringe width\n",
+"clc;\n",
+"//given data :\n",
+"a=0.10;// distance between source & prism in m\n",
+"c=1;// distance between prism & screen in m\n",
+"u=1.5;//referactive index of bi-prism\n",
+"al=%pi/180;//angle in radian\n",
+"d=2*a*(u-1)*al;// distance between slits in m\n",
+"w=5900D-10;// wavelength in m\n",
+"D=a+c;//distance between source and screen in m\n",
+"b=D*w/d;//fringes width\n",
+"disp(b,'width of fringes in meter')"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 1.8: Vertex_angle.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 1.8 // angle of vertex of biprism \n",
+"clc;\n",
+"clear;\n",
+"//given data :\n",
+"u=1.5;//referactive index of bi-prism\n",
+"b=.2D-3;//fringes width in m\n",
+"al=%pi/180;//angle in radian\n",
+"w=5D-7;// wavelength in m\n",
+"a=0.25;// distance between source & prism in m\n",
+"c=1.75;// distance between prism & screen in m\n",
+"D=a+c;//distance between source and screen in m\n",
+"d=D*w/b;//distance between slits in m\n",
+"a1=d/(2*a*(u-1));// angle in radian\n",
+"al=a1*180/%pi;// angle in degree\n",
+"vert=180-2*al;// vertex angle\n",
+"disp(vert,'angle of vertex of biprism in degree')"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 1.9: wavelength.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 1.9 // wavelength of ligth  \n",
+"clc;\n",
+"clear;\n",
+"//given data :\n",
+"u=1.5;//referactive index of bi-prism\n",
+"a=50;// distance between source & prism in cm\n",
+"c=50;// distance between prism & screen in cm\n",
+"A=179;// angle of bi-prism in degree\n",
+"D=a+c;//distance between source and screen in cm\n",
+"b=.0135;//fringes width in cm\n",
+"al=(180-A)/2;// angle with base in degree\n",
+"al=al*%pi/180;//to convert in radian\n",
+"w=2*al*(u-1)*a*b/D// wavelength in cm\n",
+"disp(w*1D8,'wavelength of light in Angstrom')"
+   ]
+   }
+],
+"metadata": {
+		  "kernelspec": {
+		   "display_name": "Scilab",
+		   "language": "scilab",
+		   "name": "scilab"
+		  },
+		  "language_info": {
+		   "file_extension": ".sce",
+		   "help_links": [
+			{
+			 "text": "MetaKernel Magics",
+			 "url": "https://github.com/calysto/metakernel/blob/master/metakernel/magics/README.md"
+			}
+		   ],
+		   "mimetype": "text/x-octave",
+		   "name": "scilab",
+		   "version": "0.7.1"
+		  }
+		 },
+		 "nbformat": 4,
+		 "nbformat_minor": 0
+}
diff --git a/Modern_Physics_for_Engineers_by_S_P_Taneja/14-crystal_structure_and_x_ray_diffraction.ipynb b/Modern_Physics_for_Engineers_by_S_P_Taneja/14-crystal_structure_and_x_ray_diffraction.ipynb
new file mode 100644
index 0000000..f5fa51b
--- /dev/null
+++ b/Modern_Physics_for_Engineers_by_S_P_Taneja/14-crystal_structure_and_x_ray_diffraction.ipynb
@@ -0,0 +1,265 @@
+{
+"cells": [
+ {
+		   "cell_type": "markdown",
+	   "metadata": {},
+	   "source": [
+       "# Chapter 14: crystal structure and x ray diffraction"
+	   ]
+	},
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 14.10: Energy_to_create_defect.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 14.10 // Energy to create defect\n",
+"clc;\n",
+"clear;\n",
+"//given data :\n",
+"a=2.82D-10;// interionic distance in m\n",
+"T=298;// temperture in kelvin\n",
+"k=8.625D-5;// Boltzmann constant eV/k\n",
+"n=5D11;// density of defects in per m3\n",
+"V=(2*a)^3;//volume of unit cell\n",
+"p=4;// no. of ion pairs\n",
+"N=p/V;// no. of ion pairs per m3\n",
+"E=2*k*T*log(N/n);// energy in eV\n",
+"disp(E, 'Energy to create defect in eV')"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 14.11: Number_of_defects.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 14.11 // no. of defects\n",
+"clc;\n",
+"clear;\n",
+"//given data :\n",
+"k=8.625D-5;// Boltzmann constant eV/k\n",
+"E=1.4;// energy to create defect in eV\n",
+"T1=293;// temperature in kelvin\n",
+"T2=573;// temperature in kelvin\n",
+"ratio=exp((-E/k)*(1/(2*T1)-1/(2*T2)));// ratio of no. of defects at T1 & T2\n",
+"format('e',10);ratio;\n",
+"disp(ratio, 'ratio of number of Frenkel defect')\n",
+"ratio=1/ratio;//\n",
+"disp(ratio,'it can be written as')"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 14.12: fraction_of_vacancy_sites.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 14.12 // fraction of vacancy sites \n",
+"clc;\n",
+"clear;\n",
+"//given data :\n",
+"f=1D-10;// fraction of vacancy sites\n",
+"T1=500;// temperature in degree\n",
+"T2=2*T1;// condition given\n",
+"T1=T1+273;// to convert in kelvin\n",
+"T2=T2+273;// to convert in kelvin\n",
+"f1=exp(T1*log(f)/T2);//new fraction\n",
+"disp(f1,'new fraction at new temperature')"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 14.4: wavelength_and_angle.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 14.4 // wavelength & angle\n",
+"clc;\n",
+"clear;\n",
+"//given data :\n",
+"d=2.82;//spacing between successive planes in A\n",
+"theta=8+35/60;//in degree\n",
+"theta=theta*%pi/180;// to convert in radian\n",
+"n=1;// order of reflection\n",
+"lamda=2*d*sin(theta) /n;//de-broglie equation\n",
+"disp(lamda,'wavelength of NaCl in A ')\n",
+"n=2;//to find angleof reflection\n",
+"theta=asin(n*lamda/(2*d));//angle of reflection radian\n",
+"theta=theta*180/%pi;// to convert in degree\n",
+"disp(theta,'angle of reflection in degree')"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 14.5: wavelength_and_speed_of_neutron.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 14.5 // wavelength & speed of neutron\n",
+"clc;\n",
+"clear;\n",
+"//given data :\n",
+"n=1;// given first reflection\n",
+"d=3.84;//spacing between successive planes in A\n",
+"m=1.67D-27;// mass of neutron in kg\n",
+"theta=30;//in degree\n",
+"theta=theta*%pi/180;// to convert in radian\n",
+"lamda=2*d*sin(theta) /n;//de-broglie equation\n",
+"disp(lamda,'wavelength of neutron in A ')\n",
+"h=6.626D-34;// plank's constant in joules-sec\n",
+"lamda=lamda*1D-10;// to convert in m\n",
+"v=h/(m*lamda);// e-Broglie relation\n",
+"disp(v,'speed of neutron in m/s')\n",
+"// in book it is wrongly calculated"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 14.6: spacing.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 14.6 // spacing d\n",
+"clc;\n",
+"clear;\n",
+"// 1st part\n",
+"theta=5+28/60;// given glancing angle in degree\n",
+"n=1;//order of reflections\n",
+"lamda=.586;// wavelength in A\n",
+"theta=theta*%pi/180;//to convert in degree\n",
+"d=n*lamda/(2*sin(theta));// spacing\n",
+"disp(d,'spacing in A')\n",
+"// in question there is a mistake \n",
+"// 2nd part\n",
+"theta=12+1/60;// given glancing angle in degree\n",
+"n=2;//order of reflections\n",
+"theta=theta*%pi/180;//to convert in degree\n",
+"d=n*lamda/(2*sin(theta));// spacing\n",
+"disp(d,'spacing in A')\n",
+"//3rd part\n",
+"theta=18+12/60;// given glancing angle in degree\n",
+"n=3;//order of reflections\n",
+"theta=theta*%pi/180;//to convert in degree\n",
+"d=n*lamda/(2*sin(theta));// spacing\n",
+"disp(d,'spacing in A')\n",
+"\n",
+"//The glancing angle is taken differently in the solution"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 14.7: glancing_angle.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 14.7 // glancing  angle\n",
+"clc;\n",
+"clear;\n",
+"//given data :\n",
+"// 1st part\n",
+"lamda=1.549;// wavelength in A\n",
+"d=4.255;// in ter planer spacing in A\n",
+"n=1;//order of reflection\n",
+"theta=asin(n*lamda/(2*d));// glacing angle in radian\n",
+"theta=theta*180/%pi;// to convert in degree\n",
+"disp(theta,'glancing angle in degree') \n",
+"// 2nd part\n",
+"n=2;//order of reflection\n",
+"theta=asin(n*lamda/(2*d));// glacing angle in radian\n",
+"theta=theta*180/%pi;// to convert in degree\n",
+"disp(theta,'glancing angle in degree') "
+   ]
+   }
+],
+"metadata": {
+		  "kernelspec": {
+		   "display_name": "Scilab",
+		   "language": "scilab",
+		   "name": "scilab"
+		  },
+		  "language_info": {
+		   "file_extension": ".sce",
+		   "help_links": [
+			{
+			 "text": "MetaKernel Magics",
+			 "url": "https://github.com/calysto/metakernel/blob/master/metakernel/magics/README.md"
+			}
+		   ],
+		   "mimetype": "text/x-octave",
+		   "name": "scilab",
+		   "version": "0.7.1"
+		  }
+		 },
+		 "nbformat": 4,
+		 "nbformat_minor": 0
+}
diff --git a/Modern_Physics_for_Engineers_by_S_P_Taneja/16-difficulties_of_classical_mechanics_abd_development_of_wave_mechanics.ipynb b/Modern_Physics_for_Engineers_by_S_P_Taneja/16-difficulties_of_classical_mechanics_abd_development_of_wave_mechanics.ipynb
new file mode 100644
index 0000000..c6450fa
--- /dev/null
+++ b/Modern_Physics_for_Engineers_by_S_P_Taneja/16-difficulties_of_classical_mechanics_abd_development_of_wave_mechanics.ipynb
@@ -0,0 +1,206 @@
+{
+"cells": [
+ {
+		   "cell_type": "markdown",
+	   "metadata": {},
+	   "source": [
+       "# Chapter 16: difficulties of classical mechanics abd development of wave mechanics"
+	   ]
+	},
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 16.1: de_broglie_wavelength.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 16.1 //de-broglie wavelength \n",
+"clc;\n",
+"clear;\n",
+"//given data :\n",
+"h=6.62D-34;// plank's constant in joules-sec\n",
+"m=9.1D-31;// mass of electron in Kg\n",
+"V=1.25D3;// Potential difference in kV\n",
+"E=V*1.6D-19;// energy associated to potential in joule\n",
+"lamda=h/sqrt(2*m*E);// formula to calculate\n",
+"disp(lamda,'de broglie wavelength in m ')\n",
+"\n",
+"//in book it is  wronglly calculated"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 16.2: Energy_of_Neutrons.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 16.2 //Energy of Neutrons  \n",
+"clc;\n",
+"clear;\n",
+"//given data :\n",
+"m=1.674D-27;// mass of neutron in kg\n",
+"h=6.60D-34;// plank's constant in joules-sec\n",
+"lamda=1D-10;// de-broglie wavelength in m\n",
+"E=h^2/(2*m*lamda^2);// energy of neutrons in joules\n",
+"E=E/1.6D-19;// to convert in eV\n",
+"disp(E,'energy of neutons in eV')"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 16.3: frequency_and_energy_of_photon.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 16.3 //frequency & energy of photon \n",
+"clc;\n",
+"clear;\n",
+"//given data :\n",
+"lamda=4D-7;// de-Broglie wavelength in m\n",
+"c=3D8;// speed of light in m/s\n",
+"h=6.62D-34;// plank's constant in joules-sec\n",
+"v=c/lamda;// frequency of photon in Hz\n",
+"E=h*v;// energy in joules\n",
+"E=E/1.6D-19;// Energy in eV\n",
+"disp(v,'frequency of photon in Hz')\n",
+"disp(E,'Energy of Photon in eV')"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 16.4: de_broglie_wavelength_of_neutrons.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 16.4 //de-broglie wavelength of neutrons \n",
+"clc;\n",
+"clear;\n",
+"//given data :\n",
+"k=1.38D-23;// Boltzmann's Constant in joules per K\n",
+"T=27;// temperature in degree\n",
+"m=1.67D-27;// mass of neutron in kg\n",
+"h=6.62D-34;// plank's constant in joules-sec\n",
+"T=T+273;// to convert in K\n",
+"lamda=h/sqrt(2*m*k*T);// De-broglie Wavelength in m\n",
+"disp(lamda,'De-broglie Wavelength in m')"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 16.5: de_broglie_wavelength.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 16.5 //de-broglie wavelength \n",
+"clc;\n",
+"clear;\n",
+"//given data :\n",
+"m=1.67D-27;// mass of proton in kg\n",
+"h=6.62D-34;// plank's constant in joules-sec\n",
+"V=2000;// potential Dfference\n",
+"ma=4*m;// mass of alpha particle in kg\n",
+"q=2*1.6D-19;// charge on alpha particle\n",
+"lamda=h/sqrt(2*ma*q*V);// formula to calculate\n",
+"disp(lamda,'de-broglie wavelength in m')"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 16.6: energy_of_photoelectrons_emitted.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 16.6 //energy of photoelectrons emitted\n",
+"clc;\n",
+"clear;\n",
+"//given data :\n",
+"h=6.62D-34;// plank's constant in joules-sec\n",
+"c=3D8;//speed of ight\n",
+"lamda=6D-7;// Threshlod wavelength in m\n",
+"v=6D14;// frequency  in Hz\n",
+"E=h*(v-c/lamda);// energy in joules\n",
+"E=E/1.6D-19;// to convert in eV\n",
+"disp(E,'energy of electrons emitted in eV')"
+   ]
+   }
+],
+"metadata": {
+		  "kernelspec": {
+		   "display_name": "Scilab",
+		   "language": "scilab",
+		   "name": "scilab"
+		  },
+		  "language_info": {
+		   "file_extension": ".sce",
+		   "help_links": [
+			{
+			 "text": "MetaKernel Magics",
+			 "url": "https://github.com/calysto/metakernel/blob/master/metakernel/magics/README.md"
+			}
+		   ],
+		   "mimetype": "text/x-octave",
+		   "name": "scilab",
+		   "version": "0.7.1"
+		  }
+		 },
+		 "nbformat": 4,
+		 "nbformat_minor": 0
+}
diff --git a/Modern_Physics_for_Engineers_by_S_P_Taneja/17-uncertainty_principle_and_schrodinger_equation.ipynb b/Modern_Physics_for_Engineers_by_S_P_Taneja/17-uncertainty_principle_and_schrodinger_equation.ipynb
new file mode 100644
index 0000000..6eda68c
--- /dev/null
+++ b/Modern_Physics_for_Engineers_by_S_P_Taneja/17-uncertainty_principle_and_schrodinger_equation.ipynb
@@ -0,0 +1,93 @@
+{
+"cells": [
+ {
+		   "cell_type": "markdown",
+	   "metadata": {},
+	   "source": [
+       "# Chapter 17: uncertainty principle and schrodinger equation"
+	   ]
+	},
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 17.1: Uncertainty_in_angle_of_Emergence.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 17.1 //Uncertainty in angle of Emergence \n",
+"clc;\n",
+"clear;\n",
+"//given data :\n",
+"E=3.2D-17;//energy of enectron in J\n",
+"m=9.1D-31;// mass of electron in kg\n",
+"h=6.626D-34;// plank's constant in J.sec\n",
+"r=1D-6;//radius of circular hole in m\n",
+"p=sqrt(2*m*E);// momentum in Kg.m/sec\n",
+"delta_x=2*r;// uncetainty in position in m\n",
+"delta_p=h/(delta_x);// uncertainty in momentum in Kg.m/sec\n",
+"delta_theta=delta_p/p;//uncertainty in angle of emergence\n",
+"disp(delta_theta,' Uncertainty in angle of Emergence in radian');\n",
+"\n",
+" //in book it is wrongly calculated"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 17.2: Uncertainty_in_frequency_and_uncertainty_in_velocity.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 17.2 //Uncertainty in frequency & uncertainty in velocity \n",
+"clc;\n",
+"clear;\n",
+"//given data :\n",
+"ha=1.0545D-34;// average  plank's constant in J.sec\n",
+"h=6.626D-34;// plank's constant in J.sec\n",
+"t=1D-8;//average time elapse in excitation in sec\n",
+"E=ha/t;// uncertainty in energy in j\n",
+"f=E/h;//Uncertainty in Energy in Hz\n",
+"disp(E,'uncertainty in energy in j')\n",
+"disp(f,'Uncertainty in Energy in Hz')"
+   ]
+   }
+],
+"metadata": {
+		  "kernelspec": {
+		   "display_name": "Scilab",
+		   "language": "scilab",
+		   "name": "scilab"
+		  },
+		  "language_info": {
+		   "file_extension": ".sce",
+		   "help_links": [
+			{
+			 "text": "MetaKernel Magics",
+			 "url": "https://github.com/calysto/metakernel/blob/master/metakernel/magics/README.md"
+			}
+		   ],
+		   "mimetype": "text/x-octave",
+		   "name": "scilab",
+		   "version": "0.7.1"
+		  }
+		 },
+		 "nbformat": 4,
+		 "nbformat_minor": 0
+}
diff --git a/Modern_Physics_for_Engineers_by_S_P_Taneja/18-free_electron_theory.ipynb b/Modern_Physics_for_Engineers_by_S_P_Taneja/18-free_electron_theory.ipynb
new file mode 100644
index 0000000..437d27c
--- /dev/null
+++ b/Modern_Physics_for_Engineers_by_S_P_Taneja/18-free_electron_theory.ipynb
@@ -0,0 +1,91 @@
+{
+"cells": [
+ {
+		   "cell_type": "markdown",
+	   "metadata": {},
+	   "source": [
+       "# Chapter 18: free electron theory"
+	   ]
+	},
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 18.1: Fermi_Energy.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 18.1 //Fermi Energy \n",
+"clc;\n",
+"clear;\n",
+"//given data :\n",
+"P=.971D3;// density in Kg/m3\n",
+"N=6D26;// Avogadro number in atoms/Kg-mole\n",
+"W=22.99;//atomic weigh of sodium\n",
+"a=N*P/W;// electron density\n",
+"m=9.1D-31;// mass of electron in kg\n",
+"h=6.626D-34;// plank's constant in joules-sec\n",
+"E=((h^2)/(2*m))*(3*a/%pi)^(2/3);// fermi energy in J\n",
+"disp(E,'Fermi energy in J')\n",
+"//in book formula taken wrongly"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 18.2: Energy_difference.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 18.2 // Energy difference  \n",
+"clc;\n",
+"clear;\n",
+"//given data :\n",
+"h=1.0545D-34;// averge Plank's constant in J-s\n",
+"m=9.1D-31;// mass of electron in kg\n",
+"a=1D-10;// dimension of box in meter\n",
+"E1=((h^2)/(2*m))*(%pi/a)^2;//fermi energy of first level in j\n",
+"E2=2*((h^2)/(m))*(%pi/a)^2;//fermi energy of second level in J\n",
+"D=E2-E1;// difference of energy \n",
+"disp(D,'energy difference in J')"
+   ]
+   }
+],
+"metadata": {
+		  "kernelspec": {
+		   "display_name": "Scilab",
+		   "language": "scilab",
+		   "name": "scilab"
+		  },
+		  "language_info": {
+		   "file_extension": ".sce",
+		   "help_links": [
+			{
+			 "text": "MetaKernel Magics",
+			 "url": "https://github.com/calysto/metakernel/blob/master/metakernel/magics/README.md"
+			}
+		   ],
+		   "mimetype": "text/x-octave",
+		   "name": "scilab",
+		   "version": "0.7.1"
+		  }
+		 },
+		 "nbformat": 4,
+		 "nbformat_minor": 0
+}
diff --git a/Modern_Physics_for_Engineers_by_S_P_Taneja/19-band_theory_of_solids.ipynb b/Modern_Physics_for_Engineers_by_S_P_Taneja/19-band_theory_of_solids.ipynb
new file mode 100644
index 0000000..1cd6136
--- /dev/null
+++ b/Modern_Physics_for_Engineers_by_S_P_Taneja/19-band_theory_of_solids.ipynb
@@ -0,0 +1,200 @@
+{
+"cells": [
+ {
+		   "cell_type": "markdown",
+	   "metadata": {},
+	   "source": [
+       "# Chapter 19: band theory of solids"
+	   ]
+	},
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 19.1: density_of_electrons_and_holes.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+" //Example 19.1 // density of electrons and holes \n",
+"clc;\n",
+"clear;\n",
+"//given data :\n",
+"//2(2%pikm/h2)^1.5=p(assume) it is a constant\n",
+"p=4.83D21;//constant\n",
+"T=300;//temperature in kelvin\n",
+"E=.7;//semiconductor with gap in eV\n",
+"k=1.38D-23;// Boltzmann constant\n",
+"d=k*T/1.6D-19;// to convert in eV\n",
+"ni=p*((300)^1.5)*exp(-1*E/d);//formula for concentration of intrinsic charge carrier\n",
+"disp(ni,'density of electrons and holes in per m3')\n",
+"// in book it is wrongly calculated"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 19.2: position_of_fermi_level.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 19.2 // position of fermi level \n",
+"clc;\n",
+"clear;\n",
+"//given data :\n",
+"//2(2%pikm/h2)^1.5=p(assume) it is a constant\n",
+"p=4.83D21;//constant\n",
+"nd=5D22;// concentration of donor atoms in atoms/m3\n",
+"T=300;// temperature  in kelvin\n",
+"k=1.38D-23;// Boltzmann constant\n",
+"E=k*T*log(p*T^1.5/nd);//formula for calcilation\n",
+"E=E/1.6D-19;//to convert in eV\n",
+"disp(E,'position of fermi level in eV')"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 19.3: position_of_fermi_level.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 19.3 // position of fermi level \n",
+"clc;\n",
+"clear;\n",
+"//given data :\n",
+"Eo=.3;// initial position in eV\n",
+"T=300;//initially temperature in kelvin\n",
+"T1=330;// final temperature in kelvin\n",
+"E=Eo*T1/T;// (formula to calculate) final position in eV\n",
+"disp(E,'new position of fermi level in eV')"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 19.4: Hall_coefficient_and_Hall_voltage.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 19.4 // Hall coefficient Hall voltage  \n",
+"clc;\n",
+"clear;\n",
+"//given data :\n",
+"p=4.83D21;//constant\n",
+"a=.428D-9;// unil cell side in m\n",
+"E=.15;// fermi level in eV\n",
+"k=1.38D-23;// Boltzmann constant\n",
+"h=6.626D-34;// plank constant in J-s\n",
+"T=300;// temperature in kelvin\n",
+"me=9.1D-31;// mass of electron in kg\n",
+"me1=.014*me;// effective mass in kg\n",
+"mh=.18*me;// effective mass of hole\n",
+"I=.1;// current in Amp\n",
+"B=.1;// magnetic field in tesla\n",
+"b=1D-3;// width of speciman in m\n",
+"n=2/a^3;// no. of atoms per unit volume\n",
+"d=k*T/1.6D-19;// to convert in eV\n",
+"e=1.6D-19;// charge of electron  \n",
+"R=1/(n*e);// Hall constant\n",
+"disp(R,'Hall coefficient for sodium in m3/C')\n",
+"// in second part InSb\n",
+"n1=2*((2*%pi*k*T/h^2)^1.5)*((me1*mh)^(3/4))*exp(-1*.15/(2*d));\n",
+"// formula for concentration in per m3\n",
+"R1=1/(n1*e);// Hall coefficient in m3/C\n",
+"V=R*I*B/b;//  Hall  voltage in V\n",
+"V1=R1*I*B/b// Hall voltage\n",
+"disp(V,'Hall voltage of sodium')\n",
+"disp(R1,'Hall coefficient for Insb in m3/C')\n",
+"disp(V1,'Hall Voltage of Insb')\n",
+"\n",
+"\n",
+""
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 19.5: energy_of_electron.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 19.5 // energy of electron \n",
+"clc;\n",
+"clear;\n",
+"//given data :\n",
+"h=6.626D-34;// plank constant in J-s\n",
+"a=.3D-9;// unit cell width in m \n",
+"p=h/(2*a);// electron momentum\n",
+"m=9.1D-31;// mass of electron in Kg\n",
+"E=p^2/(m*2);// formula for energy\n",
+"disp(p,'electron momentum in Kg m/s')\n",
+"E=E/1.6D-19;// ro convert in ev\n",
+"disp(E,'energy of electron at this momentum in eV')"
+   ]
+   }
+],
+"metadata": {
+		  "kernelspec": {
+		   "display_name": "Scilab",
+		   "language": "scilab",
+		   "name": "scilab"
+		  },
+		  "language_info": {
+		   "file_extension": ".sce",
+		   "help_links": [
+			{
+			 "text": "MetaKernel Magics",
+			 "url": "https://github.com/calysto/metakernel/blob/master/metakernel/magics/README.md"
+			}
+		   ],
+		   "mimetype": "text/x-octave",
+		   "name": "scilab",
+		   "version": "0.7.1"
+		  }
+		 },
+		 "nbformat": 4,
+		 "nbformat_minor": 0
+}
diff --git a/Modern_Physics_for_Engineers_by_S_P_Taneja/2-diffraction_of_light.ipynb b/Modern_Physics_for_Engineers_by_S_P_Taneja/2-diffraction_of_light.ipynb
new file mode 100644
index 0000000..e0dc93c
--- /dev/null
+++ b/Modern_Physics_for_Engineers_by_S_P_Taneja/2-diffraction_of_light.ipynb
@@ -0,0 +1,611 @@
+{
+"cells": [
+ {
+		   "cell_type": "markdown",
+	   "metadata": {},
+	   "source": [
+       "# Chapter 2: diffraction of light"
+	   ]
+	},
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 1.2: wavelength_of_light.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 2.2 // Wavelength of light\n",
+"clc;\n",
+"clear;\n",
+"//given data :\n",
+"a=.2D-3;//slit width in m\n",
+"D=2;// screen is placed at distance in m\n",
+"x=5D-3;// first minima lies at distance to central maxima\n",
+"w=(a*x)/D;// wavelength of light in m\n",
+"w=w*1D10;// to convert in A\n",
+"disp(w,'wavelength of light used in A')\n",
+"\n",
+""
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 2.10: difference_of_wavelength.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 2.10 //Difference of wavelengths\n",
+"clc;\n",
+"clear;\n",
+"//given data\n",
+"d_theta=.01;// change of diffraction angle\n",
+"theta=%pi/6;// diffraction angle\n",
+"w=5000;// wavelength used in A\n",
+"dw=w*d_theta*cotg(theta)//change of wavelength in A\n",
+"disp(dw,'difference of wavelength in A')"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 2.11: dispersive_power.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 2.11 // Dispersive power\n",
+"clc;\n",
+"clear;\n",
+"//given data :\n",
+"c=1/4000;// grating element\n",
+"w=5D-5;// wavelength of light in cm\n",
+"n=3;// order of spectrum\n",
+"D=n/(c*sqrt(1-((n*w/c)^2)));//dispersive power in radian per cm\n",
+"disp(D,'Dispersive power in rad/sec')\n",
+"// in book there is calculation mistake"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 2.12: resolving_power_and_wavelength.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 2.12 //Difference of wavelengths\n",
+"clc;\n",
+"clear;\n",
+"//part a\n",
+"l=5;// length of grating\n",
+"N=16000;// no. of lines per inch on the grating\n",
+"w=6000;// wavelength used in A\n",
+"n=2;// order of specrum\n",
+"T=N*l;//total no. of lines on grating\n",
+"R=T*n;// resolving power\n",
+"disp(R,'resolving power..')\n",
+"//part b\n",
+"dw=w/(T*n);// wavelength can be resolved in A\n",
+"disp(dw,'wavelength can be resolved in A')"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 2.13: resolving_power.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 2.14 //Resolving power\n",
+"clc;\n",
+"clear;\n",
+"//given data\n",
+"c=12.5D-5;// grating element in cm\n",
+"w=5D-5;// wavelength used in cm\n",
+"N=40000;//no. of lines on grating\n",
+"n=c/w;// order for maximum resolving power\n",
+"n=floor(n);//n should be integer\n",
+"P=n*N;// maximum resolving power\n",
+"disp(P,'Resolving power ')"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 2.14: resolving_power.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 2.14 //Resolving power\n",
+"clc;\n",
+"clear;\n",
+"//given data\n",
+"c=12.5D-5;// grating element in cm\n",
+"w=5D-5;// wavelength used in cm\n",
+"N=40000;//no. of lines on grating\n",
+"n=c/w;// order for maximum resolving power\n",
+"n=floor(n);//n should be integer\n",
+"P=n*N;// maximum resolving power\n",
+"disp(P,'Resolving power ')"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 2.15: radius_of_first_half_of_zone_plate.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 2.14 //Radius of half period element\n",
+"clc;\n",
+"clear;\n",
+"//given data\n",
+"f=50;//focal length of convex lens in cm\n",
+"w=5D-5;// wavelength used in cm\n",
+"n=1;// order of principal maxima\n",
+"r=sqrt(n*f*w);// radius of half period element\n",
+"disp(r,'Radius of half period element in cm')"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 2.16: position_of_spot.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 2.16 //position of brightest spot\n",
+"clc;\n",
+"clear;\n",
+"//given data\n",
+"d=.2;// diameter of ring \n",
+"n=1;//order of ring \n",
+"w=5D-5;//wavelength used in cm\n",
+"r=d/2;// radius of ring\n",
+"f=(r^2)/(w*n);//position of brightest spot \n",
+"disp(f,'position of brightest spot in cm')"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 2.17: radii_of_zones.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 2.17 //radii of transparent zone\n",
+"clc;\n",
+"clear;\n",
+"//given data\n",
+"f=1;//focal length in m\n",
+"n=1;//order of zone\n",
+"w=5893D-10;// wavelength used in m\n",
+"r=sqrt(n*f*w);//radius of transparent zone\n",
+"disp(r,'radius of tranparent in m')\n",
+"n=3;//next order\n",
+"r=sqrt(n*f*w);//radius of transparent zone\n",
+"disp(r,'radius of tranparent in m')\n",
+"n=5;//next order\n",
+"r=sqrt(n*f*w);//radius of transparent zone\n",
+"disp(r,'radius of tranparent in m')"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 2.18: focal_length_of_zone.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 2.18 // focal length of zone plate\n",
+"clc;\n",
+"clear;\n",
+"//given data :\n",
+"r=200;// radius of curvature in cm\n",
+"f=r;//principal focal length in cm\n",
+"disp(f,'principal focal length in cm') "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 2.19: angular_separation.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 2.19 //Angular sepration\n",
+"clc;\n",
+"clear;\n",
+"//given data\n",
+"n=1;// order of spectrum\n",
+"wi=.5;// width of grating in cm\n",
+"N=2500;//total no. of lines \n",
+"c=wi/N;//grating element\n",
+"w1=589D-7;// first wavelength of sodium in cm\n",
+"//part a\n",
+"theta1=asin(n*w1/c)//angular width in radian\n",
+"theta1=theta1*180/%pi;//angular width in degree\n",
+"disp(theta1,'angular width in degree')\n",
+"w2=5896D-8;//second wavelength of sodium in cm\n",
+"//part b\n",
+"theta2=asin(n*w2/c)//angular width in radian\n",
+"theta2=theta2*180/%pi;//angular width in degree\n",
+"disp(theta2,'angular width in degree')\n",
+"theta=theta2-theta1;//angular sepration degree\n",
+"disp(theta,'angular sepration in degree')\n",
+"w=(w1+w2)/2;//mid wavelength\n",
+"dw=6D-8;// change of wavelength in cm\n",
+"n=1;//order of spectrum\n",
+"N=w/(n*dw);//no. of lines will appear\n",
+"N=floor(N);// N should be integer\n",
+"if(1/c>N)\n",
+"    disp(N,'No. of lines will appear')\n",
+"else\n",
+"    disp('they can not be seen differently ')\n",
+"end"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 2.1: half_angular_width_of_central_maxima.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 2.1 // Half angular width of differation pattern\n",
+"clc;\n",
+"clear;\n",
+"//given data :\n",
+"w=6D-7;// wavelength of monochromatic light in m\n",
+"a=12D-7;// slit width in m\n",
+"theta=asin(w/a);//half angular width of central bright maxima\n",
+"theta=theta*180/%pi;// to convert in degree\n",
+"disp(theta,'Half angular width of central bright maxima in degree')"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 2.3: slit_width.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 2.3 // slit width\n",
+"clc;\n",
+"clear;\n",
+"//given data :\n",
+"w=6D-7;// wavelength of light used in m\n",
+"D=2;// screen is placed at distance in m\n",
+"x=5D-3;// first minima lies at distance to central maxima\n",
+"a=(w*D)/x;//slit width in m\n",
+"disp(a,'slit width in m')"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 2.4: angular_width_and_linear_width_of_central_maxima.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 2.4 // Angular width & linear width of central maxima\n",
+"clc;\n",
+"clear;\n",
+"//given data :\n",
+"w=589D-9;// wavelength of light used in m\n",
+"D=1;// screen is placed at distance in m\n",
+"a=.1D-3;//slit width in m\n",
+"theta=asin(w/a);//half angular width in radian\n",
+"angle=2*theta;// angular width in radian\n",
+"disp(angle,'Angular width of central maxima in radian')\n",
+"y=D*angle;// linear width of central maxima in m\n",
+"y=y*100;// to convert in cm\n",
+"disp(y,'linear width of central maxima in cm')"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 2.5: wavelength_of_light.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 2.5 // wavelength of light used\n",
+"clc;\n",
+"clear;\n",
+"//given data :\n",
+"c=1/5000;// grating element \n",
+"theta=%pi/6;//spectral line deviated \n",
+"n=2;//order of spectral line\n",
+"w=(c*sin(theta))/(n);//wavelength in cm\n",
+"w=w*1D8;//to convert in A\n",
+"disp(w,'wavelength of ligth used in A') "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 2.6: No_of_lines_in_grating.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 2.6 // minimum number of lines in grating\n",
+"clc;\n",
+"clear;\n",
+"//given data :\n",
+"w1=589D-9;//wavelength of one sodium line\n",
+"w2=5896D-10//wavelength of second line\n",
+"dw=w2-w1;//change of wavelength\n",
+"w=(w1+w2)/2;// mid wavelength\n",
+"n=1;//order of spectrum\n",
+"N=w/(n*dw);//number of lines in grating\n",
+"N=floor(N);//no. should be integer\n",
+"disp(N,'number of lines in grating')"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 2.7: order_of_spectrum.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 2.7 // order of spectrum\n",
+"clc;\n",
+"clear;\n",
+"//given data :\n",
+"w=5D-5;//wavelength of light used in cm\n",
+"c=1/5000;//grating element\n",
+"n=c/w;//order of spectrum \n",
+"disp(n,'order of spectrum')"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 2.8: Angular_separation_between_lines.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 2.8 //angular separtion\n",
+"clc;\n",
+"clear;\n",
+"//part a\n",
+"c=1/5000;//grating element\n",
+"w1=5890D-8;// in first case first wavelength used in cm\n",
+"n=2;//order of spectrum\n",
+"theta=asin((n*w1)/c);//angular separton in radian\n",
+"theta=theta*180/%pi;//to convert in degree\n",
+"disp(theta,'angular width in degree')\n",
+"//part b\n",
+"w2=5896D-8;// in second case second wavelength used in cm\n",
+"n=2;//order of spectrum\n",
+"theta1=asin((n*w2)/c);//angular separton in radian\n",
+"theta1=theta1*180/%pi;//to convert in degree\n",
+"disp(theta1,'angular width in degree')\n",
+"a=theta1-theta;//angular separation in degree\n",
+"disp(a,'angular separation in degree')\n",
+"//part c\n",
+"w=5893D-8;// mid wavelength\n",
+"dw=w2-w1;// change in wavelength\n",
+"n=2;//order of spectrum\n",
+"N=w/(dw*n);//no. of lines in grating\n",
+"N=floor(N);//N should be integer\n",
+"disp(N,'no. of lines in grating')\n",
+""
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 2.9: lines_no_of_lines_in_grating.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 2.9 //No. of lines in grating\n",
+"clc;\n",
+"clear;\n",
+"//given data\n",
+"w1=54D-6;// first wavelength used in cm\n",
+"w2=405D-7;// second wavelength used in cm\n",
+"//first wavelength  order superimposed on next higher order\n",
+"theta=%pi/6;//angle of diffraction in radian\n",
+"c=(w1*w2/(w1-w2))/sin(theta);//grating element\n",
+"N=1/c;// no. of lines per cm\n",
+"N=round(N);// N should be integer\n",
+"disp(N,'No. of lines in grating')\n",
+""
+   ]
+   }
+],
+"metadata": {
+		  "kernelspec": {
+		   "display_name": "Scilab",
+		   "language": "scilab",
+		   "name": "scilab"
+		  },
+		  "language_info": {
+		   "file_extension": ".sce",
+		   "help_links": [
+			{
+			 "text": "MetaKernel Magics",
+			 "url": "https://github.com/calysto/metakernel/blob/master/metakernel/magics/README.md"
+			}
+		   ],
+		   "mimetype": "text/x-octave",
+		   "name": "scilab",
+		   "version": "0.7.1"
+		  }
+		 },
+		 "nbformat": 4,
+		 "nbformat_minor": 0
+}
diff --git a/Modern_Physics_for_Engineers_by_S_P_Taneja/21-magnetic_properties_of_solids.ipynb b/Modern_Physics_for_Engineers_by_S_P_Taneja/21-magnetic_properties_of_solids.ipynb
new file mode 100644
index 0000000..019d758
--- /dev/null
+++ b/Modern_Physics_for_Engineers_by_S_P_Taneja/21-magnetic_properties_of_solids.ipynb
@@ -0,0 +1,89 @@
+{
+"cells": [
+ {
+		   "cell_type": "markdown",
+	   "metadata": {},
+	   "source": [
+       "# Chapter 21: magnetic properties of solids"
+	   ]
+	},
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 21.1: electron_spin_magnetic_dipole_moment.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 21.1 // electron spin magnetic dipole moment \n",
+"clc;\n",
+"clear;\n",
+"//given data :\n",
+"ub=5.6D-5;//electron spin magnetic moment in eV\n",
+"kbT=1/40;//approximate value kb(constant) & at room temperature  in eV\n",
+"u=ub/kbT;//formula\n",
+"if(u<1)\n",
+"    disp(u,'electron spin magnetic dipole moment & kbT/ub>>1')\n",
+"    \n",
+"   else\n",
+"       disp(u,'kbT/ub<<1 so it is  wrong')\n",
+"       end"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 21.2: diamagnetic_susceptibility.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 21.2 // diamagnetic susceptibility \n",
+"clc;\n",
+"clear;\n",
+"//given data :\n",
+"r=.53D-8;//(mean radius)bohr radius in cm\n",
+"N=27D23;//atomic density in per cm2\n",
+"k=2.8D-13//k=e2/mc2constants e-electron m-mass c=speed of light in cm\n",
+"X=-2*(N*k/6)*r^2;//formula for 2 electrons\n",
+"disp(X,'diamagnetic susceptibility of helium atom')"
+   ]
+   }
+],
+"metadata": {
+		  "kernelspec": {
+		   "display_name": "Scilab",
+		   "language": "scilab",
+		   "name": "scilab"
+		  },
+		  "language_info": {
+		   "file_extension": ".sce",
+		   "help_links": [
+			{
+			 "text": "MetaKernel Magics",
+			 "url": "https://github.com/calysto/metakernel/blob/master/metakernel/magics/README.md"
+			}
+		   ],
+		   "mimetype": "text/x-octave",
+		   "name": "scilab",
+		   "version": "0.7.1"
+		  }
+		 },
+		 "nbformat": 4,
+		 "nbformat_minor": 0
+}
diff --git a/Modern_Physics_for_Engineers_by_S_P_Taneja/22-superconductivity.ipynb b/Modern_Physics_for_Engineers_by_S_P_Taneja/22-superconductivity.ipynb
new file mode 100644
index 0000000..fa313d0
--- /dev/null
+++ b/Modern_Physics_for_Engineers_by_S_P_Taneja/22-superconductivity.ipynb
@@ -0,0 +1,159 @@
+{
+"cells": [
+ {
+		   "cell_type": "markdown",
+	   "metadata": {},
+	   "source": [
+       "# Chapter 22: superconductivity"
+	   ]
+	},
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 22.1: critical_field_and_transition_temperature.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 22.1 // critical field & transition temperature\n",
+"clc;\n",
+"clear;\n",
+"//given data :\n",
+"T=4.2;//to calculate critical field at T (kelvin)\n",
+"Hc1=1.4D5;// critical magnetic field in amp/m\n",
+"Hc2=4.2D5;//critical magnetic field in amp/m\n",
+"T1=14;//temperature in kelvin\n",
+"T2=13;//temperature ]in kevin \n",
+"Tc=sqrt(.5*((T2^2-T1^2)*(Hc1+Hc2)/(Hc1-Hc2)+T1^2+T2^2));// transition temperature\n",
+"H=Hc1/(1-(T1/Tc)^2);//field at 0 degree\n",
+"Hc=H*(1-(T/Tc)^2)\n",
+"disp(Tc,'transition temperature in kelvin')\n",
+"disp(Hc,'Critical field at T in amp/m')\n",
+"\n",
+"//little error due to approximations in book"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 22.2: critical_temperature.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 22.2 // critical temperature\n",
+"clc;\n",
+"clear;\n",
+"//given data :\n",
+"Tc1=4.185;//critical temperature in kelvin\n",
+"M=199.5;// isotropic mass \n",
+"M1=203.4;//isotropic mass\n",
+"Tc2=Tc1*(M/M1)^.5;// formula\n",
+"disp(Tc2,'critical temperature in kelvin') "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 22.3: critical_current_density.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 22.3 // critical current density\n",
+"clc;\n",
+"clear;\n",
+"//given data :\n",
+"d=1D-3;//diameter of wire in m\n",
+"Ho=6.5D4;//critical field at temperature at 0k\n",
+"Tc=7.18;// critical temperature in kelvin\n",
+"T=4.2;//temperature in kelvin\n",
+"Hc=Ho*(1-(T/Tc)^2);//critical field at T kelvin\n",
+"Jc=4*Hc/d;//formula\n",
+"disp(Jc,'critical current density in A/m2')"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 22.4: penetration_depth.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 22.4 // penetration depth\n",
+"clc;\n",
+"clear;\n",
+"//given data :\n",
+"w=750;// penetration depth in A\n",
+"T=3.5;// temperature in kelvin\n",
+"Tc=4.12;// critical temperature in kelvin\n",
+"d=13.55D3;//density of mercury\n",
+"N=6.023D23;// avogadro number\n",
+"M=200D-3;//molecular weight in kg \n",
+"wo=w*(1-(T/Tc)^4)^.5;//formula\n",
+"disp(wo,'penetration depth in A(angstrom)')\n",
+"//n0=d*N/M;//normal electron density at 0 degre\n",
+"//n=n0*(1-(T/Tc)^4);//electron density at T\n",
+"//disp(n)\n",
+"\n",
+"//according to question the answer is upto Wo only.\n",
+"\n",
+"\n",
+""
+   ]
+   }
+],
+"metadata": {
+		  "kernelspec": {
+		   "display_name": "Scilab",
+		   "language": "scilab",
+		   "name": "scilab"
+		  },
+		  "language_info": {
+		   "file_extension": ".sce",
+		   "help_links": [
+			{
+			 "text": "MetaKernel Magics",
+			 "url": "https://github.com/calysto/metakernel/blob/master/metakernel/magics/README.md"
+			}
+		   ],
+		   "mimetype": "text/x-octave",
+		   "name": "scilab",
+		   "version": "0.7.1"
+		  }
+		 },
+		 "nbformat": 4,
+		 "nbformat_minor": 0
+}
diff --git a/Modern_Physics_for_Engineers_by_S_P_Taneja/3-polarization_of_light.ipynb b/Modern_Physics_for_Engineers_by_S_P_Taneja/3-polarization_of_light.ipynb
new file mode 100644
index 0000000..9a731f9
--- /dev/null
+++ b/Modern_Physics_for_Engineers_by_S_P_Taneja/3-polarization_of_light.ipynb
@@ -0,0 +1,337 @@
+{
+"cells": [
+ {
+		   "cell_type": "markdown",
+	   "metadata": {},
+	   "source": [
+       "# Chapter 3: polarization of light"
+	   ]
+	},
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.10: strength_of_solution.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 3.10 // Strength of solution\n",
+"clc;\n",
+"clear;\n",
+"//given data :\n",
+"l=2;//length of solution in decimeter\n",
+"theta=12;// angle of rotation in degree\n",
+"S=60;//specific rotation in degree\n",
+"C=theta/(S*l);// concentration in gm/cc\n",
+"disp(C,'strength of solution in gm/cc')"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.11: optical_thickness_of_quarter_wave_plate.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 3.5 // Thickness of quarter wave plate\n",
+"clc;\n",
+"clear;\n",
+"//given data :\n",
+"b=.172;//bifringe of plate\n",
+"w=6D-7;// wavelength of light used in m\n",
+"t=w/(4*(b));//thickness of  in m\n",
+"t=t*100;// to convert in cm\n",
+"disp(t,'thickness of quarter wave plate in cm')"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.1: angle_of_refraction.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 3.1 // Angle of Polarization\n",
+"clc;\n",
+"clear;\n",
+"//given data :\n",
+"u=1.54;//refractive index of glass\n",
+"i=atan(u);//incidence angle in radian\n",
+"r=%pi/2 -i;//refraction angle  in radian brewester's law\n",
+"r=r*180/%pi;// to convert in degree\n",
+"disp(r,'angle of refraction in degree')"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.2: refractive_index_of_glass.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 3.2 // Refractive index of glass\n",
+"clc;\n",
+"clear;\n",
+"//given data :\n",
+"i=%pi/3;// incidence angle in radian\n",
+"//reflected and refracted rays are perpendicular to each other\n",
+"u=tan(i);//Refractive  index\n",
+"disp(u,'Refractive index of glass')"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.3: thickness_of_refracting_crystal.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 3.3 // Thickness of doubly refracting crystal\n",
+"clc;\n",
+"clear;\n",
+"//given data :\n",
+"Uo=1.55;//refractive index for O ray\n",
+"Ue=1.54;//refractive index for E ray\n",
+"w=6D-7;// wavelength of light used in m\n",
+"p=w/2;// path difference in m\n",
+"t=w/(2*(Uo-Ue));//thickness of  in m\n",
+"disp(t*1D2,'thickness of doubly refracting crystal in cm') "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.4: thickness_of_half_wave_plate.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 3.4 // Thickness of half wave plate\n",
+"clc;\n",
+"//given data :\n",
+"Uo=1.54;//Refractive index for Ordinary light\n",
+"r=1.007;//ratio of velocity of ordinary to extraordinary\n",
+"Ue=r*Uo;//refractive index for extraordinary light\n",
+"w=5893D-10;// wavelength of light used in m\n",
+"t=w/(2*(Uo-Ue));// thickness of half wave plate in m\n",
+"t=abs(t);// thickness always positive\n",
+"disp(t,'Thickness of half wave plate in m')"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.5: thickness_of_quarter_wave_plate.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 3.5 // Thickness of quarter wave plate\n",
+"clc;\n",
+"clear;\n",
+"//given data :\n",
+"Uo=1.652;//refractive index for O ray\n",
+"Ue=1.488;//refractive index for E ray\n",
+"w=546D-9;// wavelength of light used in m\n",
+"p=w/2;// path difference in m\n",
+"t=w/(4*(Uo-Ue));//thickness of  in m\n",
+"t=t*100;// to convert in cm\n",
+"disp(t,'thickness of quarter wave plate in cm') "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.6: thickness_of_calcite_plate.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 3.6 // Thickness of Calcite plate\n",
+"clc;\n",
+"clear;\n",
+"//given data :\n",
+"Uo=1.658;//refractive index for O ray\n",
+"Ue=1.486;//refractive index for E ray\n",
+"w=589D-9;// wavelength of light used in m\n",
+"n=1;//integer for odd multiples\n",
+"t=(2*n-1)*w/(4*(Uo-Ue));//thickness of Calcite plate in m\n",
+"t=t*100;// to convert in cm\n",
+"disp(t,'thickness of Calcite plate in cm')"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.7: amount_of_optical_rotation.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 3.7 // Amount of optical rotation\n",
+"clc;\n",
+"clear;\n",
+"//given data :\n",
+"Ur=1.55810;// refractive index for right handed polarized\n",
+"Ul=1.55821;//refractive index for left handed polarized\n",
+"w=4D-7;//wavelength of light used in m  \n",
+"d=.002;// thickness of plate in m\n",
+"R=%pi*d*(Ul-Ur)/w;// rotation in radian\n",
+"R=R*180/%pi;// to convert in degree\n",
+"disp(R,'Amount of optical rotation in degree')\n",
+"// in book it is wrongly calculated"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.8: phase_retardatio.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 3.8 // Phase retardation\n",
+"clc;\n",
+"clear;\n",
+"//given data :\n",
+"Uo=1.5508;//refractive index for O ray\n",
+"Ue=1.5418;//refractive index for E ray\n",
+"w=5D-7;// wavelength of light used in m\n",
+"t=.000032;// thickness of plate in m\n",
+"p=2*%pi*(Uo-Ue)*t/w;//phase retardation in radian\n",
+"disp(p,'phase retardation in radian')"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.9: specific_rotatio.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 3.9 // Specific rotation\n",
+"clc;\n",
+"clear;\n",
+"//given data :\n",
+"theta=6.5;// angle of rotation in degree\n",
+"l=2;// length of sugar solution in decimeter\n",
+"C=.05;// concentration of sugar solution\n",
+"S=theta/(l*C);//specific rotation in degree\n",
+"disp(S,'specific rotation of sugar solution in degree')"
+   ]
+   }
+],
+"metadata": {
+		  "kernelspec": {
+		   "display_name": "Scilab",
+		   "language": "scilab",
+		   "name": "scilab"
+		  },
+		  "language_info": {
+		   "file_extension": ".sce",
+		   "help_links": [
+			{
+			 "text": "MetaKernel Magics",
+			 "url": "https://github.com/calysto/metakernel/blob/master/metakernel/magics/README.md"
+			}
+		   ],
+		   "mimetype": "text/x-octave",
+		   "name": "scilab",
+		   "version": "0.7.1"
+		  }
+		 },
+		 "nbformat": 4,
+		 "nbformat_minor": 0
+}
diff --git a/Modern_Physics_for_Engineers_by_S_P_Taneja/4-Laser.ipynb b/Modern_Physics_for_Engineers_by_S_P_Taneja/4-Laser.ipynb
new file mode 100644
index 0000000..9533aec
--- /dev/null
+++ b/Modern_Physics_for_Engineers_by_S_P_Taneja/4-Laser.ipynb
@@ -0,0 +1,112 @@
+{
+"cells": [
+ {
+		   "cell_type": "markdown",
+	   "metadata": {},
+	   "source": [
+       "# Chapter 4: Laser"
+	   ]
+	},
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 4.1: Coherence_Length.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 4.1 // Coherence length for laser\n",
+"clc;\n",
+"//given data :\n",
+"v=3000;// bandwidth in Hz\n",
+"c=3D8;//speed of light in m/s\n",
+"t=1/v;//Coherence time in sec\n",
+"l=c*t;//coherence length in m\n",
+"l=l/1D3;// to convert in km\n",
+"disp(l,'Coherence length for laser in km')"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 4.2: Coherence_Length.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 4.2 // transverse Coherence length \n",
+"clc;\n",
+"//given data :\n",
+"theta=32;//angle on slit in second\n",
+"theta=32*%pi/(60*180);// to convert in radian\n",
+"w=5D-5;// wavelength of light used in cm\n",
+"C=w/theta;//coherence length in cm\n",
+"disp(C,'transverse coherence length in cm')"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 4.3: Degree_of_Non_monochromacity.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 4.3 // Degree of non-monochromacity\n",
+"clc;\n",
+"//given data :\n",
+"t=1D-10;//coherence time in sec\n",
+"c=3D8;//speed of light in m/s\n",
+"w=54D-8;// wavelength of non-monochromacity in m\n",
+"B=1/t;//bandwidth in Hz\n",
+"v=c/w;//frequency of  source\n",
+"D=B/v;// degree of non-monochromacity\n",
+"disp(D,'degree of non-monochromacity')"
+   ]
+   }
+],
+"metadata": {
+		  "kernelspec": {
+		   "display_name": "Scilab",
+		   "language": "scilab",
+		   "name": "scilab"
+		  },
+		  "language_info": {
+		   "file_extension": ".sce",
+		   "help_links": [
+			{
+			 "text": "MetaKernel Magics",
+			 "url": "https://github.com/calysto/metakernel/blob/master/metakernel/magics/README.md"
+			}
+		   ],
+		   "mimetype": "text/x-octave",
+		   "name": "scilab",
+		   "version": "0.7.1"
+		  }
+		 },
+		 "nbformat": 4,
+		 "nbformat_minor": 0
+}
diff --git a/Modern_Physics_for_Engineers_by_S_P_Taneja/5-Fiber_Optics.ipynb b/Modern_Physics_for_Engineers_by_S_P_Taneja/5-Fiber_Optics.ipynb
new file mode 100644
index 0000000..e44fa12
--- /dev/null
+++ b/Modern_Physics_for_Engineers_by_S_P_Taneja/5-Fiber_Optics.ipynb
@@ -0,0 +1,152 @@
+{
+"cells": [
+ {
+		   "cell_type": "markdown",
+	   "metadata": {},
+	   "source": [
+       "# Chapter 5: Fiber Optics"
+	   ]
+	},
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 5.1: Numerical_Aperture.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 5.1 \n",
+"clc;\n",
+"// 1st part //critical angle\n",
+"u1=1.48;// refractive index of cladding\n",
+"u2=1.5;// refractive index of core\n",
+"u=1;// refractive index of air\n",
+"theta=asin(u1/u2);// critical angle in radian\n",
+"theta=theta*180/%pi;// to convert in degree\n",
+"disp(theta,'critical angle in degree')\n",
+"// 2nd part //fractional refractive index\n",
+"Fr=(u2-u1)/u2;// fractional refractive index\n",
+"Fr=Fr*100;// to convert in percent\n",
+"disp(Fr,'fractional refractive index in percentage')\n",
+"// 3rd part // acceptance angle\n",
+"A=asin(sqrt(u2^2-u1^2));// Acceptance angle in radian\n",
+"disp(A,'Acceptance angle in radian')\n",
+"// 4th part //numerical aperture\n",
+"NA=sin(A);// Numerical aperture\n",
+"disp(NA,'Numerical aperture ')"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 5.2: Number_of_Modes.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 5.2 \n",
+"clc;\n",
+"// 1st part // V number\n",
+"NA=.22;// Numerical aperture\n",
+"a=50/2;// radius of core\n",
+"w=.850;//wavelength in um\n",
+"V=2*%pi*a*NA/w;// V number\n",
+"disp(V,'V number')\n",
+"// 2nd part // number of modes\n",
+"N=(V^2)/4;// number of modes\n",
+"disp(N,'number of modes')"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 5.3: Refractive_Index.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 5.3 // refractive index  \n",
+"clc;\n",
+"// given data\n",
+"NA=.22;//Numerical Aperature\n",
+"Fr=.012;//Fractional refractive index\n",
+"u1=NA/sqrt(Fr*(2-Fr));// refractive index of core\n",
+"u2=sqrt(u1^2-NA^2);// refractive index of clad\n",
+"disp(u1,'Refractive index of core')\n",
+"disp(u2,'Refractive index of clad')"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 5.4: Numerical_Aperture.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 8.2 // Numerical Aperture & acceptance angle\n",
+"clc;\n",
+"//given data :\n",
+"u1=1.62;//refractive index of core\n",
+"u2=1.52;// refractive index of clad\n",
+"A=asin(sqrt(u1^2-u2^2));// acceptance angle in radian\n",
+"NA=sin(A);// numerical aperture\n",
+"A=A*180/%pi;// to convert in degree\n",
+"disp(A,'Acceptance angle in degree')\n",
+"disp(NA,'Numerical Aperture')"
+   ]
+   }
+],
+"metadata": {
+		  "kernelspec": {
+		   "display_name": "Scilab",
+		   "language": "scilab",
+		   "name": "scilab"
+		  },
+		  "language_info": {
+		   "file_extension": ".sce",
+		   "help_links": [
+			{
+			 "text": "MetaKernel Magics",
+			 "url": "https://github.com/calysto/metakernel/blob/master/metakernel/magics/README.md"
+			}
+		   ],
+		   "mimetype": "text/x-octave",
+		   "name": "scilab",
+		   "version": "0.7.1"
+		  }
+		 },
+		 "nbformat": 4,
+		 "nbformat_minor": 0
+}
diff --git a/Modern_Physics_for_Engineers_by_S_P_Taneja/6-oscillatory_motion.ipynb b/Modern_Physics_for_Engineers_by_S_P_Taneja/6-oscillatory_motion.ipynb
new file mode 100644
index 0000000..421020a
--- /dev/null
+++ b/Modern_Physics_for_Engineers_by_S_P_Taneja/6-oscillatory_motion.ipynb
@@ -0,0 +1,274 @@
+{
+"cells": [
+ {
+		   "cell_type": "markdown",
+	   "metadata": {},
+	   "source": [
+       "# Chapter 6: oscillatory motion"
+	   ]
+	},
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 6.1: Equilibrium_position_time.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 6.1 // Equilibrium position time \n",
+"clc;\n",
+"clear;\n",
+"//given data :\n",
+"A=.05;//Amplitude of SHM in m\n",
+"T=6;// period in sec\n",
+"Xo=A;// equilibrium position at t=0 position in m\n",
+"X=.025;//equilibrium position  in m\n",
+"w=2*%pi/T;// angular frequency in rad/sec\n",
+"ph=asin(Xo/A);// phase angle in radian\n",
+"t=(asin(X/A)-ph)/w// time for equilibrium position in sec\n",
+"t=abs(t);// it take positive magnitude\n",
+"disp(t,'time to move from Equilibrium position in sec') "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 6.2: Maximum_velocity_in_SHM.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 6.2 // Maximum velocity in SHM \n",
+"clc;\n",
+"clear;\n",
+"//given data :\n",
+"A=.06;// Amplitude of SHM in m\n",
+"T=31.4;// period in sec\n",
+"w=2*%pi/T;// angular frequency in rad/sec\n",
+"V=A*w;// maximum velocity in m/s\n",
+"disp(V,'Maximum velocity in m/s' )"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 6.3: Period_of_Oscillation.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 6.3 // Period of Oscillation \n",
+"clc;\n",
+"clear;\n",
+"//given data :\n",
+"l=1;// length of pendulum in m\n",
+"m=1;// mass of pendulum in kg\n",
+"g=9.8;//acceleration of gravity in m/s2\n",
+"T=2*%pi*sqrt(l/g);//time period\n",
+"disp(T,'Period of Oscillation in sec')"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 6.4: period_of_oscillatio.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 6.4 // Period of Oscillation \n",
+"clc;\n",
+"clear;\n",
+"//given data :\n",
+"m1=8;// mass suspended in kg\n",
+"l=.32;// length of spring stretched in m\n",
+"m=.5;// new mass suspended in kg\n",
+"g=9.8;//acceleration of gravity in m/s2\n",
+"k=m1*g/l;// force constant  of spring in N/m\n",
+"disp(k)\n",
+"T=2*%pi*sqrt(m/k);// time period of Oscillation\n",
+"disp(T,'Time Period of Oscillation sec')\n",
+"// in book it is wrongly calculated"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 6.6: oscillation_time.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 6.6 // oscillation time \n",
+"clc;\n",
+"clear;\n",
+"//given data :\n",
+"r=10;//ratio of energies \n",
+"Q=1D4;//quality factor\n",
+"v=250;// frequency of fork in cycles/s\n",
+"w=2*%pi*v;//angular frequency in rad/sec\n",
+"T=Q/w;// relaxation time in sec\n",
+"t=T*log(r);// time in sec\n",
+"disp(t,'time to become new energy in sec')\n",
+""
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 6.7: Equilibrium_position_time.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 6.7 // Equilibrium position time \n",
+"clc;\n",
+"clear;\n",
+"//given data :\n",
+"r=exp(2);//ratio of amplitude\n",
+"Q=2D3;//quality factor\n",
+"v=240;// frequency of fork in cycles/s\n",
+"w=2*%pi*v;//angular frequency in rad/sec\n",
+"T=Q/w;// relaxation time in sec\n",
+"t=2*T*log(r);//time for ne amplitude\n",
+"disp(t,'time to become for new amplitude in sec')"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 6.8: Q_factor_and_half_width_of_power_resonance.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 6.8 \n",
+"clc;\n",
+"clear;\n",
+"//part a :\n",
+"Ao=.1;// amplitude at minimum frequency in mm\n",
+"A=100;//maximum amplitude\n",
+"Q=A/Ao;//quality factor\n",
+"disp(Q,'Quality factor')\n",
+"//part b\n",
+"w=100;//resonance frequency in rad/sec\n",
+"T=Q/w;//energy decay time\n",
+"disp(T,'energy decay time in sec')\n",
+"//part c\n",
+"hw=1/(2*T);// half width of power resonance curve\n",
+"disp(hw,'half width of power resonance curve in rad/sec')"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 6.9: amplitude_of_oscillations_and_relative_phase.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 6.9 // amplitude of oscillations & relative phase  \n",
+"clc;\n",
+"clear;\n",
+"//given data :\n",
+"m=.1;//suspended mass in kg\n",
+"k=100;// force constant in N/m\n",
+"Fo=2;// maximum driving force in N\n",
+"p=1;// constant in Ns/m\n",
+"Wo=sqrt(k/m);//angular frequency in rad/sec in steady state;\n",
+"W=50;//angular frequency in rad/sec\n",
+"f=Fo/m;\n",
+"d=p/(2*m);//damping constant\n",
+"B=f/sqrt(((Wo^2)-(W^2))^2+4*(d^2)*(W^2));//amplitude of Oscillation in m\n",
+"delta=atan(2*d*W/(Wo^2-W^2));// relative phase in radian\n",
+"disp(B,'amplitude of oscillations in m')\n",
+"delta=delta*180/%pi +180;// to convert in 0 t0 180 in degree\n",
+"disp(delta,'relative phase in degree')"
+   ]
+   }
+],
+"metadata": {
+		  "kernelspec": {
+		   "display_name": "Scilab",
+		   "language": "scilab",
+		   "name": "scilab"
+		  },
+		  "language_info": {
+		   "file_extension": ".sce",
+		   "help_links": [
+			{
+			 "text": "MetaKernel Magics",
+			 "url": "https://github.com/calysto/metakernel/blob/master/metakernel/magics/README.md"
+			}
+		   ],
+		   "mimetype": "text/x-octave",
+		   "name": "scilab",
+		   "version": "0.7.1"
+		  }
+		 },
+		 "nbformat": 4,
+		 "nbformat_minor": 0
+}
diff --git a/Modern_Physics_for_Engineers_by_S_P_Taneja/7-electromagnetic_waves.ipynb b/Modern_Physics_for_Engineers_by_S_P_Taneja/7-electromagnetic_waves.ipynb
new file mode 100644
index 0000000..d2a4cca
--- /dev/null
+++ b/Modern_Physics_for_Engineers_by_S_P_Taneja/7-electromagnetic_waves.ipynb
@@ -0,0 +1,179 @@
+{
+"cells": [
+ {
+		   "cell_type": "markdown",
+	   "metadata": {},
+	   "source": [
+       "# Chapter 7: electromagnetic waves"
+	   ]
+	},
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 7.1: Energy_of_plane_wave.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 7.1 // Energy of plane wave\n",
+"clc;\n",
+"clear;\n",
+"//given data :\n",
+"u=(4D-7*%pi);// permeability(free space) in H/m\n",
+"e=8.85D-12;// permitivity(free space) in Farad/m\n",
+"H=1;// magnetic field in amp/m\n",
+"E=H*sqrt(u/e);// formula to calculate\n",
+"disp(E,'magnitude of Energy of plane wave in V/m')"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 7.2: impedence_of_medium_and_peak_magnetic_field.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 7.2\n",
+"clc;\n",
+"clear;\n",
+"// 1st part //impedence of medium\n",
+"ur=1;//relative permeability\n",
+"er=2;//relative permitivity\n",
+"uo=(4D-7*%pi);// permeability(free space) in H/m\n",
+"eo=8.85D-12;// permitivity(free space) in Farad/m\n",
+"u=ur*uo;//permeability(medium) in H/m\n",
+"e=er*eo;//permitivity(medium) in Farad/m\n",
+"Z=sqrt(u/e);// impedence of medium\n",
+"disp(Z,'impedence of medium in ohm')\n",
+"// 2nd part //peak magnetic field intensity\n",
+"Eo=5;//peak electric field strength in V/m\n",
+"Ho=Eo/Z;// Intensity of magnetic field in A/m\n",
+"disp(Ho,'Intensity of magnetic field in A/m')\n",
+"// 3rd part //velocity of electromagnetic wave\n",
+"v=1/sqrt(u*e);//velocity in m/s\n",
+"disp(v,'velocity of magnetic field in m/s')"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 7.3: wavelength_of_wave_and_amplitude_of_magnetic_field.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 7.3\n",
+"clc;\n",
+"clear;\n",
+"// 1st part //wavelength of wave\n",
+"f=3D11;//frequency of wave in Hz\n",
+"c=3D8;// speed of light in m/s\n",
+"w=c/f;// wavelength in m\n",
+"disp(w,'wavelength of wave in m')\n",
+"// 2nd part // amplitude of Oscillating magnetic field\n",
+"Eo=50;// amplitude of electric field in V/m\n",
+"Bo=Eo/c;// ocillating magnetic field in Tesla\n",
+"format('e',10);Bo\n",
+"disp(Bo,'approx amplitude of oscillating magnetic field in T')"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 7.4: solar_energy.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 7.4 // solar energy\n",
+"clc;\n",
+"clear;\n",
+"//given data :\n",
+"r=1.5D11;//distance from sun to earth\n",
+"P=3.8D26;//power radiated by sun\n",
+"N=P/(4*%pi*(r^2));// poyting vector (average energy)\n",
+"N=N*60/4.2D4 ;//to convert watt/m2 into cal/cm2.min\n",
+"N=ceil(N);\n",
+"disp(N,' average solar energy in cal/cm2.min')"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 7.5: Dielelctric_constant.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 7.5 // Dielelctric constant\n",
+"clc;\n",
+"clear;\n",
+"//given data :\n",
+"v=.62;// velocity factor of coaxial\n",
+"Er=1/v^2;// relative permittivity constant\n",
+"disp(Er,'dielectric constant of insulator')"
+   ]
+   }
+],
+"metadata": {
+		  "kernelspec": {
+		   "display_name": "Scilab",
+		   "language": "scilab",
+		   "name": "scilab"
+		  },
+		  "language_info": {
+		   "file_extension": ".sce",
+		   "help_links": [
+			{
+			 "text": "MetaKernel Magics",
+			 "url": "https://github.com/calysto/metakernel/blob/master/metakernel/magics/README.md"
+			}
+		   ],
+		   "mimetype": "text/x-octave",
+		   "name": "scilab",
+		   "version": "0.7.1"
+		  }
+		 },
+		 "nbformat": 4,
+		 "nbformat_minor": 0
+}
diff --git a/Modern_Physics_for_Engineers_by_S_P_Taneja/8-Dielectrics.ipynb b/Modern_Physics_for_Engineers_by_S_P_Taneja/8-Dielectrics.ipynb
new file mode 100644
index 0000000..86dd6f6
--- /dev/null
+++ b/Modern_Physics_for_Engineers_by_S_P_Taneja/8-Dielectrics.ipynb
@@ -0,0 +1,146 @@
+{
+"cells": [
+ {
+		   "cell_type": "markdown",
+	   "metadata": {},
+	   "source": [
+       "# Chapter 8: Dielectrics"
+	   ]
+	},
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 8.1: polarisation_and_Energy_density.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 8.1 // Dielectric\n",
+"clc;\n",
+"clear;\n",
+"//given data :\n",
+"k=3;// Dielectric constant\n",
+"E=1D6;// field intensity in V/m2\n",
+"e=8.85D-12;// permitivity in C2/N.m2\n",
+"P=e*(k-1)*E;// polarisation in C/m2\n",
+"disp(P,'polarisation in C/m2')\n",
+"D=k*e*E;// displacement vector in C/m2\n",
+"disp(D,'Displacement in C/m2')\n",
+"ED=.5*k*e*E^2;// Energy Density in Joules/m3\n",
+"disp(ED,'Energy density in joules/m3')"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 8.2: Dipole_moment_of_slab.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 8.2 // Dipole moment of slab\n",
+"clc;\n",
+"clear;\n",
+"//given data :\n",
+"D=5D-4;// displacement vector magnitude in m2\n",
+"P=4D-4;// Polarisation  vector magnitude  in m2\n",
+"E=D-P;// Field Intensity in m2\n",
+"V=.5;// volume of slab in m3 \n",
+"k=D/E;// dielectric contant \n",
+"p=P*V;//total dipole moment in m5\n",
+"disp(k,'Dielectric constant')\n",
+"disp(p,'total dipole contant in m5')"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 8.3: electric_susceptibility.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 8.3 // electric susceptibility\n",
+"clc;\n",
+"clear;\n",
+"//given data :\n",
+"k=1.000038;//dielectric constant\n",
+"x=k-1;//electric susceptibility\n",
+"disp(x,'electric susceptibility')"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 8.4: Dipole_moment.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example 8.4 // Dipole moment\n",
+"clc;\n",
+"clear;\n",
+"//given data :\n",
+"E=100;// Field Intensity in V/m\n",
+"k=1.000074;// dielectric contant\n",
+"e=8.85D-12;// permitivity in Farad/m\n",
+"p=22.4D-3;// dipole moment\n",
+"N=6D23/(22.4D-3);// no. of atoms per unit volume at NTP\n",
+"p=e*(k-1)*E/N;//  dipole moment in C-m\n",
+"disp(p,'total moment in C-m')"
+   ]
+   }
+],
+"metadata": {
+		  "kernelspec": {
+		   "display_name": "Scilab",
+		   "language": "scilab",
+		   "name": "scilab"
+		  },
+		  "language_info": {
+		   "file_extension": ".sce",
+		   "help_links": [
+			{
+			 "text": "MetaKernel Magics",
+			 "url": "https://github.com/calysto/metakernel/blob/master/metakernel/magics/README.md"
+			}
+		   ],
+		   "mimetype": "text/x-octave",
+		   "name": "scilab",
+		   "version": "0.7.1"
+		  }
+		 },
+		 "nbformat": 4,
+		 "nbformat_minor": 0
+}
diff --git a/Modern_Physics_for_Engineers_by_S_P_Taneja/80-Dielectrics.ipynb b/Modern_Physics_for_Engineers_by_S_P_Taneja/80-Dielectrics.ipynb
new file mode 100644
index 0000000..541994d
--- /dev/null
+++ b/Modern_Physics_for_Engineers_by_S_P_Taneja/80-Dielectrics.ipynb
@@ -0,0 +1,32 @@
+{
+"cells": [
+ {
+		   "cell_type": "markdown",
+	   "metadata": {},
+	   "source": [
+       "# Chapter 80: Dielectrics"
+	   ]
+	},
+],
+"metadata": {
+		  "kernelspec": {
+		   "display_name": "Scilab",
+		   "language": "scilab",
+		   "name": "scilab"
+		  },
+		  "language_info": {
+		   "file_extension": ".sce",
+		   "help_links": [
+			{
+			 "text": "MetaKernel Magics",
+			 "url": "https://github.com/calysto/metakernel/blob/master/metakernel/magics/README.md"
+			}
+		   ],
+		   "mimetype": "text/x-octave",
+		   "name": "scilab",
+		   "version": "0.7.1"
+		  }
+		 },
+		 "nbformat": 4,
+		 "nbformat_minor": 0
+}